package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@WebFilter(urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter{
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        long id = Thread.currentThread().getId();
        log.info("线程id为：{}",id);

        //1、获取本次请求的URI
        String uri = request.getRequestURI();// /backend/index.html

        log.info("请求的路径为：{}",uri);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",      //对登录请求放行
                "/employee/logout",     //对退出请求放行
                "/backend/**",       //对后台管理系统中的所有静态页面放行
                "/front/**",        //对所有移动端的页面放行
                "/common/download", //下载文件
                "/common/upload",   //上传文件
                "/user/sendMsg",    //发送短信
                "/user/login"       //登录
        };

        //2、判断本次请求是否需要处理
        boolean check = check(urls, uri);

        //3、如果不需要处理，则直接放行
        if(check){
            filterChain.doFilter(request,response);
            return;
        }

        //4、判断登录状态，如果已登录，则直接放行
        Object employee = request.getSession().getAttribute("employee");
        if(employee != null){
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request,response);
            return;
        }
        //4-2、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        R<Object> r = R.error("NOTLOGIN");
        response.getWriter().write(JSON.toJSONString(r));
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean flag = PATH_MATCHER.match(url, requestURI);
            if(flag){
                return true;
            }
        }
        return false;
    }
}